DESCRIPTION: (Applicant's Abstract) Open-angle glaucoma (OAG) is a major cause of blindness and visual impairment, especially in black populations. Although reported family history is known to be associated with the disease, few studies have actually examined the family members to determine the presence or absence of OAG. The Barbados Family Study of Open-Angle Glaucoma (BFSG) is the first study designed to provide accurate data on the familial aggregation of OAG in a large black population. Its ultimate goals are to determine the pattern of OAG transmission within families and then identify its potential genetic component. This study is related to the Barbados Eye Study (BES), a prevalence study, 1987-1992, and the Barbados Incidence Study of Eye Diseases (BISED), 1992-1997. Among the 4,709 BES participants (84 percent of those eligible), a high OAG prevalence of 7 percent was found. Male gender and family history of OAG were associated with OAG. To achieve BFSG aims, the surviving parents, siblings, spouses and children (age 40+ years) of 100 BES and BISED participants with OAG, who meet our criteria, will be examined to determine their OAG status and obtain risk factor information. The examination of the estimated 680 relatives will include applanation tonometry, best corrected visual acuity, automated perimetry, stereo fundus photography, an interview, ocular and other measurements, as well as collection of a blood sample for genetic analyses. In the first phase of data analyses, SAGE (Statistical Analysis for Genetic Epidemiology) and other statistical methods will be used to determine the genetic mode of transmission of OAG. The identification of affected families, sample collection and epidemiological analysis will allow the second phase of the analyses, which will consist of linkage analyses of OAG using highly polymorphic microsatellite markers. The BFSG results should not only increase our understanding of the inheritance of OAG, but may have direct clinical applicability by allowing prediction of family members who are at increased risk for developing this disease.